30 Sketch of a Classif cation of the European Rods. 



In offering the annexed sketch of a classification of European 

 rocks to the 'attention of the reader, it is merely my intention to show 

 that divisions can be made for practical purposes, independent of the 

 theoretical terras primitive, transition, secondary and tertiary ; terms 

 which, not being founded on an enlarged view of nature, but ground- 

 ed on peculiar views, now doubted, there would appear no good rea- 

 son for preserving. It is not presumed that this classification will 

 be adopted, and I am well aware that many just objections can be 

 made to it; but it pretends to nothing beyond convenience: and if 

 geologists could be induced to use something of this kind, or any 

 other that would better answer the purpose of relieving us from the 

 old theoretical terms, I cannot hut imagine that the science would 

 derive benefit from the change. 



In the accompanying Table, rocks are first divided into stratified 

 and unstratified, a natural division, or at all events one convenient 

 for practical purposes, independent of the theoretical opinions that 

 may be connected with each of these two great classes of rocks. 

 The same may perhaps also be said of the next great division ; viz. 

 that of the stratified rocks into superior or fossiliferous, and inferior 

 or non-fossiliferous. The superior stratified or fossiliferous rocks 

 are divided into groups, nearly the same as those w^hich I published 

 in the Annales des Sciences JVaturelles for August last- I have my- 

 self found them useful in practice, more particularly in the examina- 

 tion of districts distant from each other. 



Stratified Rocks. — Group 1. [Alluvial) seems at first sight 

 natural and easily determined; but in practice it is often very diffi- 

 cult to say where it commences. When we take into consideration 

 the great depth of many ravines and gorges which appear to origin- 

 ate in the cutting power of existing rivers^ the cliffs even oT the 

 hardest rocks which more or less bound any extent of coast, and the 

 immense accumulations of comparatively modern land, as for in- 

 stance, those great flats on the western side of Soudi America, there 

 is a difficulty in referring these phaenomena to the duration of a com- 

 paratively short period of time. Geologically speaking, the epoch is 

 recent; but, according to our general ideas of time, it appears to be 

 one that reaches back far beyond the dates usually assigned to the 

 present order of things. Man and the monkey tribe seem to be the 

 most marked new creation qf this epocli. I would by no means be 



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